Search

Abstract Psyllid species, including the potato psyllid (PoP) Bactericera cockerelli (Sulc) (Triozidae) serve as host and vector of “Candidatus Liberibacter spp.” (“Ca. Liberibacter”), which also infects diverse plant hosts, including citrus and tomato. Psyllid transmission of “Ca. Liberibacter” is circulative and propagative. The time of “Ca. Liberibacter” acquisition and therefore vector life stage most competent for bacterial transmission varies by pathosystems. Here, the potato psyllid-“Ca. Liberibacter solanacearum” (CLso) pathosystem was investigated to dissect CLso-prophage interactions in the tomato plant and PoP-psyllid host by real-time quantitative reverse transcriptase amplification of CLso genes/loci with predicted involvement in host infection and psyllid-CLso transmission. Genes/loci analyzed were associated with (1) CLso-adhesion, -invasion, -pathogenicity, and -motility, (2) prophage-adhesion and pathogenicity, and (3) CLso-lysogenic cycle. Relative gene expression was quantified by qRT-PCR amplification from total RNA isolated from CLso-infected 1st–2nd and 4th–5th nymphs and teneral adults and CLso-infected tomato plants in which CLso infection is thought to occur without SC1-SC2 replication. Gene/loci expression was host-dependent and varied with the psyllid developmental stage. Loci previously associated with repressor-anti-repressor regulation in the “Ca Liberibacter asiaticus”-prophage pathosystem, which maintains the lysogenic cycle in Asian citrus psyllid Diaphorina citri, were expressed in CLso-infected psyllids but not in CLso-infected tomato plants.

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts.

The Featured Creatures collection provides in-depth profiles of insects, nematodes, arachnids and other organisms relevant to Florida. These profiles are intended for the use of interested laypersons with some knowledge of biology as well as academic audiences.

Objective: The date palm, Phoenix dactylifera L., is an ancient and valuable tree that provides food and other products. The date palm trees are attacked by several pests, including the red palm weevil, which is devastating to date palm plantations. Knowledge of the functionality of entomopathogenic fungi, including Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) species, in the tree trunk is critical for controlling date palm weevil and other pests. The goal of this study was to assess the movement of the entomopathogenic fungus, B. bassiana, within the date palm tree. Methods: Beauveria bassiana (BbSA-4) mixed with food colors was trunk-injected using a balloon injector into healthy date palm plants. Trunks were cut into one-meter logs 2, 20, and 86 days post-injection. Each log was further dissected into four quarters to examine the present of the fungus. The appearance of food colors and the detection of fungal spores at different heights from the point of injection revealed the translocation of B. bassiana within the trunk. The samples were taken from several locations where food color could be visible, and the distance traveled by the fungal spores was measured. Results: The injected palm tissue samples were cultured on PDA media in the laboratory, and the present of fungal spores was confirmed. B. bassiana (BbSA-4) was found to be surviving in all treated date palm trees. The survival rate of isolate BbSA-4 averaged 70.5%, 34.9%, and 13.9% from dissected trunks examined at 2, 20, and 86 days, respectively, after injection. Isolate BbSA-4 was more apparent in the trunk after spiral injected than bottom injection. The findings revealed that using an entomopathogenic fungus as an endophytic to supplement IPM programs could be beneficial.

The stability of resistance to fenpropathrin was assessed using five populations of Diaphorina citri with varying initial resistances ranging from fully susceptible (SS) to fully resistant (RR). Furthermore, we quantified the relative expression of voltage-gated sodium channel (VGSC) genes in crosses of field-selected and laboratory-susceptible D. citri lines after eight months without insecticide selection. We found that resistance to fenpropathrin remained elevated up to eight months after exposure to fenpropathrin. A real-time quantitative PCR analysis using the susceptible baseline population revealed that levels of VGSC gene expression were significantly higher in the RS75 cross and the RR100 fully resistant line eight months after their last fenpropathrin exposure. Our results suggest that while fenpropathrin resistance is likely unstable under field conditions when interbreeding with susceptible individuals is possible, resistance can remain stable for at least 8 months if those populations are isolated. Further, insecticide rotation and the maintenance of susceptible reservoirs of individuals should mitigate fenpropathrin resistance in D. citri over time. The development of a VGSC gene biomarker may be a useful tool for monitoring pyrethroid resistance in D. citri going forward.

The Asian citrus psyllid (ACP) is a citrus pest and insect vector of “Candidatus Liberibacter asiaticus”, the causal agent of citrus greening disease. Double-stranded RNA (dsRNA) biopesticides that trigger RNA interference (RNAi) offer an alternative to traditional insecticides. Standardized laboratory screening of dsRNA requires establishing the minimal effective concentration(s) that result in effective RNAi “penetrance” and trigger RNAi, resulting in one or more measurable phenotypes, herein, significant gene knockdown and the potential for mortality. In this study, knockdown was evaluated for a range of dsRNA concentrations of three ACP candidate genes, clathrin heavy chain (CHC), vacuolar ATPase subunit A (vATPase-A), and sucrose non-fermenting protein 7 (Snf7). Gene knockdown was quantified for ACP teneral adults and 3rd instar nymphs allowed a 48 h ingestion-access period (IAP) on 10, 50,100, 200, and 500 ng/µL dsRNA dissolved in 20% sucrose followed by a 5-day post-IAP on orange jasmine shoots. Significant gene knockdown (p < 0.05) in ACP third instar nymphs and adults ranged from 12–34% and 18–39%, 5 days post-IAP on dsRNA at 10–500 and 100–500 ng/µL, respectively. The threshold concentration beyond which no significant gene knockdown and adult mortality was observed post-48 h IAP and 10-day IAP, respectively, was determined as 200 ng/µL, a concentration indicative of optimal RNAi penetrance.

Panonychus citri is a phytophagous mite of economic importance in open citrus orchards and a major pest in Citrus Under Protective Screen (CUPS), a new undercover production system tested in Florida. Immatures and adults feed on citrus leaves, fruits, and green twigs resulting in mesophyll collapse, shoot dieback, and fruit drop. In Florida, P. citri occurs throughout the year but is most abundant in spring or early summer and autumn or early winter. Although chemical sprays like Abamectin or Fenbutatin oxide provide some control of P. citri, resistance has been reported in different regions of the world. Several predatory insects and mites have been shown to attack the mite and could be potential natural enemies to use in biological control programs.

Huanglongbing (HLB) or citrus greening disease is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Vector control is considered a basic component of HLB management even under high disease incidence scenarios. While vector management heavily relies on the application of synthetic chemical sprays, overuse of insecticides raises several concerns including insecticide resistance, environmental impacts, and secondary pest outbreaks. The present study aims to compare the effects of three different economic thresholds (ET-0.2, 0.5, 1.0) and one calendar-based application schedule on the incidence of D. citri and beneficial species in plots of commercially grown citrus, as well as end-of-season yield and overall management costs. The results suggest that reducing spray frequency from eight to as few as three sprays per year had little effect on counts of pest and beneficial insects in the field. The numbers of D. citri and that of a secondary weevil pest were similar between plots treated with the calendar-based spray plots and plots managed with the ET-1.0. Furthermore, spider numbers were higher in the ET-1.0 plots, while ant numbers were lower compared with calendar sprayed plots. Management input costs were lower under economic thresholds (ET-0.5–ET-1.0) than with monthly calendar-based sprays, while yield losses were only slightly greater in the lower threshold of 0.2 mean psyllids per tap than with calendar sprays. Overall, management savings of more than 100% made up for this difference. Together, these results suggest that implementing a spray program of rotated chemistries based on an economic threshold of 0.5–1.0 adult psyllids per stem tap could provide both economic and ecological benefits. We discuss the implications of such an approach in the context of a young citrus tree protection program and the greater goals of sustainable citrus production under HLB.

The circadian rhythm involves multiple genes that generate an internal molecular clock, allowing organisms to anticipate environmental conditions produced by the Earth’s rotation on its axis. Here, we present the results of the manual curation of 27 genes that are associated with circadian rhythm in the genome of Diaphorina citri, the Asian citrus psyllid. This insect is the vector for the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening disease (Huanglongbing). This disease severely affects citrus industries and has drastically decreased crop yields worldwide. Based on cry1 and cry2 identified in the psyllid genome, D. citri likely possesses a circadian model similar to the lepidopteran butterfly, Danaus plexippus. Manual annotation will improve the quality of circadian rhythm gene models, allowing the future development of molecular therapeutics, such as RNA interference or antisense technologies, to target these genes to disrupt the psyllid biology.

Asian citrus psyllid (ACP) are at the mercy of their host (citrus) for survival. They need flush to lay eggs and for the nymphs to develop. Prior to HLB, the majority of flushing had been fairly predictable and occurred in the early spring and late summer. The occurrence of flush in young trees is less predictable during the summer rainy season. Although HLB infection has affected the predictability of major flushes, the winter cold period in January and February remains a time when most mature trees have little or no significant new growth. This is a time when ACP reproduction is most restricted and when populations naturally decline. Application of a broad-spectrum insecticide during the winter months has become a well-known technique for managing psyllids. Previous research has demonstrated that if ACP populations are effectively reduced during the dormant winter period, it is easier to keep them down with subsequent sprays later in the season.

Citrus greening (huanglonbing (HLB)) disease has drastically reduced citrus fruit production in Florida over the last two decades. Scientists have developed sustainable nutrient management practices to live with the disease and continue fruit production. Best pesticide management practices have been devised to reduce the spread of HLB by Asian citrus psyllid (ACP). However, soil application of excessive nutrients and the use of soil drench application of pesticides to huanglongbing-infected citrus groves have been a serious environmental concern since the recent development of resistance to some pesticides. It is important to understand the consequences of applying pesticides and nutrients beyond the recommended application rates with an inappropriate method for citrus growth and development. Alternatively, foliar sprays of some nutrients proved effective to meet plants’ requirements, and foliar sprays of effective insecticide products could provide an adequate mode of action for group rotation to minimize insecticide resistance by ACP and other pests. Sustainability in citrus production systems should include best management practices that improve pesticide and nutrient efficiency by including the total maximum daily load exiting the grove to reduce pesticide and nutrient exports into waterbodies.

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama is an economically important pest of citrus because it vectors the causal pathogens of huanglongbing (HLB) or citrus greening disease. Biological control is an important component of citrus pest management but requires consistent strengthening of its impact on pest complex. The brown lacewing Sympherobius barberi Banks is a known predator of several insect pests from Asia, Europe, and America. However, there is not much information about its effectiveness against D. citri. We evaluated S. barberi against the D. citri and frozen eggs of the Mediterranean flour moth Ephestia kuehniella, the latter is a common diet used for rearing predators in laboratories. Adult S. barberi successfully fed on D. citri eggs and nymphs under both light and dark conditions. Diaphorina citri was also suitable for the development and reproduction of S. barberi except for slightly prolonged larval development compared with E. kuehniella diet. The egg hatch from the total number of eggs laid on D. citri and E. kuehniella diets averaged 65% and 52%, respectively. Females laid 64% eggs on dimpled white paper compared to 36% combined on plain paper and leaves of citrus, orange jasmine, eggplant and cantaloupe. Sympherobius barberi released at densities of 2–6 adults against eggs and nymphs of D. citri on infested orange jasmine plants in the cages provided a reduction of 43–81% in the number of provided eggs or nymphs. In the field tests on D. citri infested citrus trees, reduction averaged 35% in five cohorts in which developing colonies of 28–32 nymphs were provided to one S. barberi per cage. Findings suggest the significant potential of S. barberi as a predator of D. citri and to contribute to reducing huanglongbing.

Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important economic pest of citrus crops because it vectors the causal pathogen of huanglongbing (HLB; aka citrus greening). Population suppression of D. citri with insecticides has been disproportionally relied on for HLB management and a greater diversity of more sustainable tools is needed. Periglandula spp. is a fungal endosymbiont (family Clavicipitaceae) that forms a mutualistic relationship with members of plants in family Convolvulaceae. This association results in the production of ergot alkaloids that were previously documented as having psyllicidal properties. We investigated the mortality and behavior of D. citri exposed to crude extracts from morning glories in the plant family Convolvulaceae, as well as synthetic ergot alkaloids. Nymphs and adults were exposed to the crude plant extracts from Periglandula positive species of Convolvulaceae, as well as five synthetic ergot alkaloids. Treatments were prepared by exposing clippings of citrus to 100 ng/µL of crude extract from Periglandula-positive species of Ipomoea (I. imperati, I. leptophylla, I. pandurata and I. tricolor), and Turbina corymbosa, and from one Periglandula-negative species (I. alba) (100 ng/µL). Mortality of adult and nymphal D. citri was significantly higher than the control after exposure to extracts from I. tricolor and I. imperati. The synthetic ergot alkaloids, lysergol (10–100 ng/µL), ergonovine maleate (100 ng/µL), agroclavine (10–100 ng/µL), and ergosine (10–100 ng/µL) increased mortality of D. citri nymphs, while ergosine (100 ng/µL) and agroclavine (100 ng/µL) increased mortality of adults compared to water controls. Fewer D. citri adults settled on plants treated with crude extracts or synthetic ergot alkaloids than on water controls at 48 h after release. D. citri that fed on citrus leaves treated with 10 ng/μL solution of crude extract from the Periglandula-positive species Ipomoea (I. imperati, I. leptophylla, I. pandurata, I. tricolor), and Turbina corymbosa excreted significantly less honeydew compared with a negative water control and extract from Periglandula-negative species (I. alba). Our results indicate that crude extracts and ergot alkaloids exhibit toxic and sub-lethal effects on D. citri that could be useful for management of this pest.

Citrus greening disease is devastating the citrus industry in Florida, and the conventional synthetic pesticide applications used to control the vector, the Asian citrus psyllid (AsCP), Diaphorina citri, are rapidly becoming unsustainable. Various laboratory experiments indicate that the entomopathogenic fungus Cordyceps javanica, alone and in combination with horticultural oils, may offer a more sustainable strategy for the management of AsCP. Field studies conducted in 2018 and 2019 in mature citrus indicated that C. javanica alone, C. javanica mixed with white oil, and the chemical standard spinetoram mixed with white oil significantly suppressed AsCP adult populations by 61–83% up to 14 days after treatment in 2018, although colony-forming units of C. javanica were still present on the leaves 21 days after treatment (DAT). Only spinetoram + oil significantly suppressed AsCP, by 100%, up to 7 DAT in 2019. Natural enemies of AsCP, including lady beetles, lacewing larvae and the parasitoid Tamarixia radiata, were observed in the fungal treatments and the untreated control. The AsCP suppression by C. javanica and its compatibility with beneficial organisms suggest the potential use of this entomopathogenic fungus in citrus-integrated pest management.

Citrus production under enclosed structures can exclude the Asian citrus psyllid (ACP, Diaphorina citri) and eliminate the negative effects of citrus greening or huanglongbing (HLB) disease caused by Candidatus Liberibacter asiaticus to the grapefruit (Citrus paradisi) fresh fruit industry. Physically impeding the insect vector from accessing trees is a logical method to have disease-free groves. Our objectives were to assess the ability of enclosed screenhouses to exclude the ACP, stop HLB inoculation and dissemination, and improve fruit yield of in-ground and container-grown 6-year-old “Ray Ruby” grapefruit at super-high planting densities relative to open-air trees. We built a large structure to allow commercial-scale trials and tested two production systems (screenhouse and open-air), two planting systems (in-ground and potted), and two rootstocks (“Sour Orange” [Citrus × aurantium] and “US-897” [Citrus reticulata × Poncirus trifoliate]). The experimental design was a randomized complete block design split-split-plot with four replications. Four passively ventilated 1,080-m2 completely enclosed screenhouses were constructed using a 50-mesh monofilament high-density polyethylene screen. The main support for each enclosed, covered structure consisted of pressure-treated, wooden utility poles. Trees were planted in Sept/2013 on a density of 1,957 trees/ha. Irrigation was performed on-demand using two 7.6-LPH drip emitters per tree, and fertigation was applied three times/week using 15N-2.6P-22.4K water-soluble fertilizer at 180 kg N/ha. Psyllids were monitored using sticky cards and detected inside the screenhouses post-Hurricane Irma, which damaged the screen structures in Sept/2017, leaving openings until repairs were completed in Apr/2018. Screen aging and a tropical storm in April/2019 caused another major screen opening fixed in Oct/2019. Despite the weather-related damages to the screens, only trees cultivated in open-air tested positive for Candidatus Liberibacter asiaticus after 6 years. There was fast disease progression for all outside treatments, with 100% infection. Covered, in-ground trees exhibited the highest trunk diameter and canopy volume (P < 0.0001). Trees grown inside screenhouses exhibited higher fruit yield than outside trees, with the highest yield observed for in-ground trees on “US-897” (51,081 kg/ha) (P < 0.0001). Several open-air treatments particularly in containers did not produce any fruit. On the other hand, potted grapefruit trees cultivated inside the enclosures had the highest soluble solids content (P < 0.001). The screenhouses provided disease exclusion, increased fruit yield, and fruit quality, representing an alternative for growers interested in producing high-quality fruit for the fresh market. Production cost and economic viability still need to be evaluated for large-scale implementation.

This 7-page fact sheet is part of the 2019–2020 Florida Citrus Production Guide. Written by J. A. Qureshi and P. A. Stansly, and published by the Entomology and Nematology Department, March 2019. ENY-603/CG002: 2022–2023 Florida Citrus Production Guide: Rust Mites, Spider Mites, and Other Phytophagous Mites (ufl.edu)

This document is a two-page quick reference guide to citrus insecticides and miticides recommended in the Florida Citrus Pest Management Guide, their effects on important citrus pests, and their natural enemies. It is a minor revision written by L. M. Diepenbrock, P. A. Stansly, L. L. Stelinski, J. D. Burrow, and J. A. Qureshi, and published by the Entomology and Nematology Department, August 2019. ENY-854/IN807: 2022-2023 Quick Reference Guide to Citrus Insecticides and Miticides (ufl.edu)

Florida citrus is a trailblazer for incorporation of IPM in US agriculture. We believe a return is not only possible but could be very beneficial. Returning to a more sustainable paradigm could also coincide with economic reward. Implementation of thresholds and timing sprays to flushing should maximize the impact of spraying. The above example from Stansly and Monzo indicates that one well-timed dormant spray followed by 3 additional sprays triggered by a 0.2 psyllids / tap action threshold can provide equal or greater economic return than 10 calendar sprays in the same grove. Reducing sprays allows buildup of the biological control agents already present in Florida and allows them to work for you. Diversifying selection forces complicates development of resistance for the insect population. Resistance to one tactic can be compensated for by the others. Therefore, the IPM system can be further improved by not only allowing biological control to do its work by reducing insecticide input, but also by incorporating cultural controls. Psyllid exclusion technologies, such as protective screening and kaolin clay, are proving effective. Protecting grove borders with targeted sprays can reduce costs of whole-grove sprays. Significant progress has also been made toward reducing psyllid access to young citrus by planting on UV reflective mulches. Finally, IPM-based management will likely benefit from area-wide implementation. Many of the tools for practicing IPM in Florida citrus are already here; however, it takes integration to assemble the puzzle in practice. Peer reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazine July 22, 2019

This 9-page fact sheet is part of the 2018–2019 Florida Citrus Production Guide. Written by P. A. Stansly, J. A. Qureshi, L. L. Stelinski, and M. E. Rogers, and published by the Department of Entomology and Nematology, January 2019.

This 6-page fact sheet is part of the 2018–2019 Florida Citrus Production Guide. Written by M. E. Rogers, P. A. Stansly, and J. A. Qureshi, and published by the Entomology and Nematology Department, January 2019. ENY-603/CG002: 2022–2023 Florida Citrus Production Guide: Rust Mites, Spider Mites, and Other Phytophagous Mites (ufl.edu)

Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple sensory modalities (vision, olfaction, and gustation,) to locate and accept host plants. We explored incorporation of several sensory cues into a multi-modal attract-and-kill device (AK device) using a three-dimensional shape to increase visibility, as well as elements of color, attractant, phagostimulant, UV reflectant, and toxicant. Attraction of adult D. citri to the device was mediated by a combination of a highly reflective yellow cylinder, a UV reflectant compound (magnesium oxide), and an odorant blend as a short-range attractant. The device surface was coated with a slow-release wax matrix (SPLAT™) augmented with a phagostimulant consisting of a 3-component blend (formic acid, acetic acid, and para-cymene) and an insecticide (β-cyfluthrin). Psyllids landing on the device attempted to feed from the wax matrix, became intoxicated, died, and fell from the device. The device remained fully active over a period of 12 weeks partly because dead psyllids or nontargets did not adhere to the surface as occurs on adhesive yellow sticky cards, the industry standard. Laboratory and field assays showed that the device attracted and killed significantly more adult D. citri than ordinary yellow sticky cards. This device or a future iteration based on the design elements of this device is expected to contribute to sustainable and environmentally appropriate management of D. citri by exploiting the psyllid’s innate behavioral responses to visual, olfactory, and gustatory stimuli.

This 5-page fact sheet is part of the 2018–2019 Florida Citrus Production Guide. This section is focused on sucking insects which affect foliage, twigs, and fruit of citrus in Florida. Insects covered here include scales, mealybugs, whiteflies, and aphids that can impact the health of young and mature trees and fruit quality. They differ from each other in their biology, generation times, and injury to plant, but approaches to monitoring and management are similar. Individual discussions of some groups are provided, and the tables of management options are organized by active ingredient, with the target pests from this chapter in bold text. Written by P. A. Stansly, J. A. Qureshi, L. L. Stelinski, L. M. Diepenbrock, and M. E. Rogers, and published by the Department of Entomology and Nematology, May 2018. ENY-604/CG004: 2022–2023 Florida Citrus Production Guide: Rust Mites, Spider Mites, and Other Phytophagous Mites (ufl.edu)

Root weevils are a major pest group for many kinds of plants, with at least nine species that colonize citrus. Species commonly infesting citrus include Diaprepes root weevil (Diaprepes abbreviates), blue-green citrus root weevils (Pachnaeus litus and Pachnaeus opalus), little leaf notcher (Artipus floridanus), Fuller rose beetle (Asynonychus godmani) and Sri Lanka weevil (Myllocerus undecimpustulatus undatus). Peer-reviewed through UF/IFAS Citrus Research and Education Center; published in Citrus Industry Magazine January 3, 2018.

This new field sheet provides information on Tap sampling for Asian Citrus Psyllid (ACP). Monitoring ACP populations is an important tool in the integrated management of citrus greening. The most efficient way to estimate field populations of this insect is by monitoring adults. Tap sampling has proven to provide data needed to make informed decisions for managing this insect pest. Written by Phil Stansly and Jawwad A. Qureshi, and published by the Entomology and Nematology Department, January 2016. ENY-887/IN1116: TAP Sampling for Asian Citrus Psyllid (ACP) Field Sheet (ufl.edu)

In the High Plains of western Kansas, USA, the convergent lady beetle Hippodamia convergens Guérin completes a spring generation feeding on cereal aphids in winter wheat before leaving fields in large numbers around the time of harvest. In late May, large aggregations of coccinellids form on wild sunflowers, Helianthus annuus, and certain other weeds, that appear to serve as important sources of water absorption for the beetles, and other beneficial insects, during the dry prairie summer. Adult beetles were collected from sunflower plants and held in four treatments: (1) access to water only, (2) access to sunflower stalks only, (3) eggs of Ephestia kuehniella provided ad libitum + water and, (4) greenbug, Schizaphis graminum Rondani provided ad libitum. Most females fed greenbug matured eggs in less than a week and only a few entered reproductive diapause. In contrast, more than half of the females fed Ephestia eggs, an inferior diet, entered reproductive diapause, and those that matured eggs required an average of almost three weeks to do so. Time to 50% mortality was 7 days for beetles receiving only water, and 12 days for those receiving only sunflower stalks, whereupon all survivors were fed greenbug. Even after feeding on greenbugs for a month, less than half of the surviving females in these two treatments produced eggs. We conclude that reproductive diapause is an important adaptation for improving H. convergens survival during summer when aphids are scarce, although females will forgo diapause if they have continuous access to high quality prey.

Three techniques are currently in use to sample adult Asian citrus psyllids (ACP). This 7-page illustrated fact sheet by H. A. Arevalo, J. A. Qureshi, and P. A. Stansly discusses the strengths and weaknesses of each and makes recommendations for routine monitoring of ACP for management purposes. Includes references. Published by the UF Department of Entomology and Nematology, September 2010.